code: def add_var_declaration(self, size):
      var_name = self.get_var_name()
      self.add_var_assignment(
          var_name=var_name,
          value="array()" if size > 1 else "null",
          value_size=size,
      )
      return var_name
  
file_path: m2cgen/m2cgen/interpreters/php/code_generator.py
imports: from contextlib import contextmanager
  from m2cgen.ast import CompOpType
  from m2cgen.interpreters.code_generator import CLikeCodeGenerator, CodeTemplate
label_desc: Use image node_id 4 for calling the PhpCodeGenerator obj's underlying member method code with example usage: obj.add_var_declaration(size) and returns: var_name